Field of the Invention
The present invention generally relates to a multi-step transmission for a vehicle and, more particularly, to a multi-step transmission technology able to realize as many shifting positions as possible using the fewest parts possible and the simplest configuration possible.
Description of Related Art
Recent rising oil prices have driven worldwide car manufacturers into unlimited competition to improve fuel efficiency. In addition, great efforts have been made to reduce the weight and improve the fuel efficiency of engines based on a variety of techniques such as downsizing.
Among methods that can be sought for transmissions equipped in vehicles to improve fuel efficiency, there is a method able to improve fuel efficiency by allowing an engine to operate at more efficient operation points using a multi-step transmission.
Such a multi-step transmission allows an engine to operate in a relatively low RPM (revolutions per minute) range, thereby further improving the quietness of a vehicle.
However, as the number of shifting positions of a transmission increases, the number of internal parts constituting the transmission also increases. This may lead to undesirable effects instead, such as the reduced mountability and transfer efficiency and the increased cost and weight of the transmission. Therefore, in order to maximize the effect of improved fuel efficiency using a multi-step transmission, it is important to devise a transmission structure able to realize maximum efficiency using a relatively small number of parts and a simple configuration.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.